Device for the automatic fixing of control cams on their shaft in a zig-zag stitch sewing machine



March 1959 R. CASAS-ROBERT ET AL 2,379,732

DEVICE FOR THE AUTOMATIC FIXING OF CONTROL CAMS ON THEIR SHAFT IN A ZIG-ZAG STITCH SEWING MACHINE Filed Sept. 7, 1955 INVENTO Ramon Chaos-Ro Marcel Fresard.

I ATTORNEY Ramon Casas-Robert and Marcel Fresard, Geneva, Switzerland, assignors to Melina S.A., Fribourg, Switzerland, a corporation of Switzerland Application September 7, 1955, Serial No. 532,930

Claims priority, application Switzerland November 3, 1954 4 Claims. (Cl. 112158) In zig-zag stitch sewing machines, of the type dis closed in U.S. Patent No. 2,653,557, in which the lateral movements of oscillation of the needle bar and those of the feeder are controlled: automatically by interchangeable cams, the latter are secured to the camcarrying shaft by means of a clamping nut. This method of securing increases the time necessary for changing the cams by reason of the necessity of unscrewing and tightening the nut each time, without considering the risks of losing the latter.

The subject of the present invention is a device for the automatic fixing of control cams of a zig-zag stitch sewing machine, on their shaft for the lateral movements of the needle bar and those of the feeder, char acterized in that the cam shaft carries a support for the cams, said shaft having a hub on which the cams are placed, said hub comprising at least a spring locking member which recedes automatically into the hub whilst a cam is placed in position on the latter and coming into engagement with the central part of the cam, for maintaining it in position, when it is in position, a control member being located on the hub for controlling the withdrawal of the locking member against the action of its spring, for the purpose'of removing the cams.

One form of construction of the subject of the invention is shown diagrammatically and by way of example in the accompanying drawings, wherein:

Fig. l is a view in vertical section.

Fig. 2 is a view in perspective.

Fig. 3 is a view of a detail to a larger scale.

With reference to the drawing, the cam-carrying shaft 1 is mounted in a support 2 adapted to be secured to the framework of the machine by screws 3. Said shaft carries at its lower end a helicoidal wheel 4 gearing with a worm 5 mounted on the driving shaft 6 of the machine.

On the shaft 1 is mounted a cam support 7 provided with a hub 8 on which the cams 9 slide freely. For preventing them from turning on the hub they are provided on one of their faces with a recess 10 with which engages a projection 11 of the support 7.

In the example shown, the two control cams form a single part, the cam A actuating the oscillating support of the needle bar through the medium of a lever 12, whilst the cam B actuates the feeder through the medium of a control shaft 13.

"The device for securing the cams AB comprises three oscillating locking members 14, subjected to the action of springs and located in radial and longitudinal slots 16 of the hub 8. Each member 14 is formed by a lever hinged at one of its ends, located in one of the Patentedv Mar. 31, 1959 2. slots 16, to the hub, the other end thereof being urged, outwardly by a spring 15 The part of the lever 14 projecting from the slot 16 of the hub 8, has an inclined portion 17.

The arrangement, is such that when one pair of cams AB is. placed on the hub 8, it comes into contact with the inclined part 17 of the'bolts 14 and repels them into the interior of the slots 16'until its lower face is in contact with that of the cam support 7. At this moment, the ends of the bolts come into engagement with the edge of the upper face of the pair of cams and hold it in position.

For controlling the withdrawal of the bolts 14 into the interior of the hub 8' for the purpose of removal of the cams, a control member is provided, formed by a sleeve 18 sliding freely on the hub and of whichv the edge comes into contact with the inclined portion 17 of the bolts.

When moving the sleeve 18 axially, the bolts 14 are repelled towards the interior of the hub 8 against the action of their springs and the cams AB can bewithdrawn from the hub.

In order to retain the sleeve 18 on the hub 8, it is provided with a base'having in its central portion a depression with an opening. Through the latter passes freely the stem of a screw 19 screwed into the end of the shaft 1 and of which the head is sunk into the said depression.

- In order to disengage thecams automatically from the hub'8, when actuating the sleeve 18, a separate device.

is provided. it is formed by an annular member 20 car,- r'ying three arms 21' bent at a right angle was to be lodged in longitudinal grooves 22 of the hub. The ends 23 of the arms 21 are 'curved in such a manner as to come into contact with the lower face of the cams AB. The member 20 which forms an ejector, is subjected to the action of a coiled spring 24 hearing against the end of the hub 8.

With this device, when a pair of cams AB is set in position on the hub, the spring 24 is compressed, as shown in Fig. 1. When the sleeve 18 is actuated for pushing the bolts 14 into the interior of the hub, at the moment at which their ends release the edge of the cams, the spring 24 expands and moves the member 20 axially whereby the ends 23 of the arms 21 move the cams and disengage them from the hub.

" their upper face so as to bring the bolts 14 into engage ment therewith.

In order to disengage the cams from the hub 8, it is sufi'icient to press upon the sleeve 18.

We claim:

1. For a zig-zag stitch sewing machine comprising a laterally oscillative needle bar and a feeder member, the combination comprising cam means for automatically oscillating said needle bar and for automatically actuating said fecder'member, a cam shaft, a hub mounted about said cam shaft, said cam'means being mounted about said hub, and means for both automatically fixing said cam means about said hub and ejecting said cam means therefrom, said means including a cam ejector slidable axially with respect to said huh and said cam shaft, said cam ejector positioned about said hub and engaging the lower face of said cam means, said cam ejector member having a top portion annular with respect to the cam shaft, said top portion being spaced from the top surface of said hub, spring means positioned about said cam shaft between and engaging the top surface of said hub and the bottom surface of said top portion of said cam ejector for moving said cam ejector axially of said hub, at least one spring-loaded cam locking means pivotally mounted in the outer surface of said hub for engaging said cam means, said cam locking means having a portion outwardly inclined with respect to the outer surface of said hub, a sleeve positioned about said hub and said cam ejector and operatively connected to said cam shaft, said sleeve being slidable axially of said hub and said cam shaft and said cam ejector, the bottom edge of said sleeve engaging said cam locking means at its outwardly inclined portion, whereby the cam means is engaged by said cam locking means .upon positioning of the said cam means about the shaft and whereby said sleeve, upon being actuated against said cam locking means, causes the cam locking means to disengage from the cam means thereby allowing said spring means to urge said c'am ejector upwardly to move said cam means axially of the shaft from its fixed position.

2. For a zig-zag stitch sewing machine comprising a laterally oscillative needle bar, a feeder member, the

combination comprising cam means for automatically oscillating said needle bar and forautomatically actuating said feeder member, said cam means being operatively connected to both said needle bar and said feeder, a cam shaft support member, a cam shaft member on said cam shaft support member, a hub member mounted about said cam shaft member, said cam means being mounted about said hub member, said hub member hating a plurality of radially spaced longitudinal grooves on its outer surface and at least one radially spaced longitudinal slot therein, and means for both automatically fixing said cam means about said hub member and eject ing said cam means therefrom, said means being operatively associated with both said cam shaft member and said hub member, said means including a cam ejector member having a top portion annular with respect to the cam shaft member and radially spaced right angle arms each depending from said top portion and slidably engaging each of the said plurality of radially spaced longitudinal grooves on the outer surface of said hub memeaih of said. right angle. arms having an outwardly about and spacedfrom the shaft and ejecting said cam turned end portion engaging the lower face of said cam member, said top portion being spaced from the top surface of said hub member, spring means positioned about said cam shaft member between and engaging the top surface of said. hub member and the bottom surface of said top portion of said cam ejector member for moving said cam ejector member upwardly and axially of said hub member, at least one spring-loaded cam locking means pivotally mounted in said radially spaced longitudinal slot for engaging said cam means, said cam locking means having a portion outwardly inclined with respect to the outer surface of said hub member, a sleeve member positioned about said hub member and the arms of said cam ejector member and operatively connected to said cam shaft member, said sleeve member being slidable axially of said hub member and said cam shaft member and said cam ejector member, the bottom edge of said sleeve member engaging said cam locking member at its outwardly inclined portion, whereby said springloaded cam locking member recedes into said hub slot while the cam means is positioned about the shaft memher and hub member and then engages said cam means to lock said cam means in position about said hub member and whereby said sleeve member, upon being actuated against said cam locking member, causes said locking member to recede into said hub slot thereby allowing said 4 spring means to urge said cam ejector member upwardly to move said cam means axially of the shaft from its fixed position.

3. For a zig-zag stitch sewing machine comprising a laterally oscillative needle bar and a feeder member, cam means for automatically oscillating said needle bar and for automatically actuating said feeder member, a cam shaft, said cam means being mounted about and spaced from said shaft; the improved means for both automatically fixing the cam means about and spaced from the shaft and ejecting the cam means therefrom including a hub mounted about said cam shaft, a cam ejector slidable axially with respect to the hub and cam shaft, said hub being positioned between said shaft and said cam means, said cam ejector being positioned about the hub and engaging the lower face of the cam means, said cam ejector member having a top portion annular with respect to the cam shaft, said top portion being spaced from the top surface of the hub, spring means positioned about the cam shaft between and engaging the top surface of the hub and the bottom surface of said top portion of said cam ejector for moving said cam ejector axially of said hub, at least one spring-loaded cam locking means pivotally mounted in the outer surface of the hub for engaging the cam means, said cam locking means having a portion outwardly inclined with respect to the outer surface of the hub, a sleeve positioned about the hub and said cam ejector and operatively connected to the cam shaft, saidsleeve being slidable axially of the hub and the cam shaft and said cam ejector, the bottom edgeof said sleeve engaging said cam locking means at its outwardly inclined portion, whereby the cam means is engaged by said cam locking means upon positioning of the said cam means about the shaft and whereby said sleeve, upon being actuated against said cam locking means, causes the cam locking means to disengage from the cam means thereby allowing said spring means to urge said cam ejector upwardly to move said cam means axially of the shaft from its fixed position.

, 4. For a zig-zagstitch sewing machine comprising a laterally oscillative needle bar, a feeder member, cam means for automatically oscillating said needle bar and for automatically actuating said feeder member, said cam means being operatively connected to both said needle bar and said feeder, a cam shaft member on said cam shaft support'member, said cam means being mounted about and spaced from said cam shaft; the improved means for both automatically fixing said cam means means therefrom including a cam, ejector having a top portion annular with respect to the camshaft member and radially spaced right angle arms each depending from said top portion, a hub member mounted about the cam shaft and positioned between said cam shaft and said cam means, said hub member having a plurality of radially spaced longitudinal grooves on its outer surface and at least one radially spaced longitudinal slot therein, said radially spaced right angle arms slidably engaging each of said plurality of radially spaced longitudinal grooves on the outer surface of said hub member, each of said right angle arms having an outwardly turned end portion engaging the lower face of said cam member, said top portion being spaced from the top surface of said hub member, spring means positioned about the cam shaft member between and engaging the top surface of said hub member and the bottom surface of said top portion of said cam ejector member for moving said cam ejector member upwardly and axially of said hub member, at least one spring-loaded cam locking means pivotally mounted in said radially spaced longitudinal slot for engaging said cam means, said cam locking means having a portion outwardly inclined with respect to the outer surface of said hub member, a sleeve member positioned about said hub member and the arms of said cam ejector 5 member and operatively connected to said cam shaft member, said sleeve member being slidable axially of said hub member and said cam shaft member and said cam ejector member, the bottom edge of said sleeve member engaging said cam locking member at its outwardly inclined portion, whereby said spring-loaded cam locking member recedes into said hub slot while the cam means is positioned about the shaft member and hub member and then engages said cam means to lock said cam means in position about said hub member and whereby said sleeve member, upon being actuated against said cam References Cited in the file of this patent UNITED STATES PATENTS 2,009,371 Junge July 23, 1935 Stacey Aug. 5, 1941 

